A recent joint operation by customs officers in the provinces of Yunnan, Shandong and Henan busted 11 cross-border criminal gangs that were smuggling human hair, customs officers said in Kunming, Yunnan, on Sunday.

During the operation in January, which was organized by the General Administration of Customs, officers seized a large amount of human hair and arrested 48 suspects in a case involving 1.1 billion yuan ($168 million).

The smugglers bought the hair in Myanmar, then smuggled it into China, mainly by hiding it in vehicles.

The groups had smuggled about 1,200 metric tons of hair since 2017, the officers said.

Pan Lei, an officer with the Tengchong branch of Kunming customs' anti-smuggling bureau, said domestic demand for high-end wigs made with real human hair has been increasing each year, and there is a huge price difference for human hair between the domestic and foreign markets, so smugglers looked to hair for huge profits.

The seized hair was from India, Pakistan and Myanmar.

It was sorted by length, with longer hair worth more, he said. For example, smugglers spent 220 yuan abroad to buy a kilogram of hair that was 25 centimeters long, which they could sell to domestic wig manufacturers for 940 yuan, Pan said.

The smugglers were well organized and had a complete smuggling network, said Dai Rulong, an officer with the Tengchong branch.

Kunming customs noticed that a huge number of packages containing hair and wigs were being sent to Shandong, Anhui and other provinces, which attracted their attention because there is little record of hair imports or associated businesses in Yunnan province.

Smugglers used walkie-talkies rather than telephones to communicate with each other to avoid being discovered.

In addition, they usually operated at night and arranged guards along the route to watch out for inspectors, Dai said.

The importation of human hair is prohibited in China, said Ouyang Dong, deputy head of the Tengchong branch.

The joint operation destroyed a cross-border criminal chain and would promote the regulation of human hair use in the domestic market, Ouyang said.